/*
 * Copyright © 2008 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

/*
 * Matrix interfaces
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include <string.h>
#include "pixman-private.h"

#define F(x)	pixman_int_to_fixed(x)

PIXMAN_EXPORT void
pixman_transform_init_identity(struct pixman_transform *matrix)
{
	int	i;

	memset(matrix, '\0', sizeof (struct pixman_transform));
	for (i = 0; i < 3; i++)
		matrix->matrix[i][i] = F(1);
}

typedef pixman_fixed_32_32_t	pixman_fixed_34_30_t;

PIXMAN_EXPORT pixman_bool_t
pixman_transform_point_3d(const struct pixman_transform *transform,
			  struct pixman_vector *vector)
{
	struct pixman_vector result;
	pixman_fixed_32_32_t partial;
	pixman_fixed_48_16_t v;
	int i, j;

	for (j = 0; j < 3; j++)
	{
		v = 0;
		for (i = 0; i < 3; i++)
		{
			partial = ((pixman_fixed_48_16_t) transform->matrix[j][i] *
				   (pixman_fixed_48_16_t) vector->vector[i]);
			v += partial >> 16;
		}
		if (v > pixman_max_fixed_48_16 || v < pixman_min_fixed_48_16)
			return FALSE;
		result.vector[j] = (pixman_fixed_t) v;
	}
	*vector = result;
	if (!result.vector[2])
		return FALSE;
	return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_point(const struct pixman_transform *transform,
		       struct pixman_vector *vector)
{
	pixman_fixed_32_32_t partial;
	pixman_fixed_34_30_t v[3];
	pixman_fixed_48_16_t quo;
	int i, j;

	for (j = 0; j < 3; j++)
	{
		v[j] = 0;
		for (i = 0; i < 3; i++)
		{
			partial = ((pixman_fixed_32_32_t) transform->matrix[j][i] * 
				   (pixman_fixed_32_32_t) vector->vector[i]);
			v[j] += partial >> 2;
		}
	}
	if (!v[2])
		return FALSE;
	for (j = 0; j < 2; j++)
	{
		quo = v[j] / (v[2] >> 16);
		if (quo > pixman_max_fixed_48_16 || quo < pixman_min_fixed_48_16)
			return FALSE;
		vector->vector[j] = (pixman_fixed_t) quo;
	}
	vector->vector[2] = pixman_fixed_1;
	return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_multiply (struct pixman_transform *dst,
			   const struct pixman_transform *l,
			   const struct pixman_transform *r)
{
	struct pixman_transform d;
	int dx, dy;
	int o;

	for (dy = 0; dy < 3; dy++)
		for (dx = 0; dx < 3; dx++) {
			pixman_fixed_48_16_t    v;
			pixman_fixed_32_32_t    partial;
			v = 0;
			for (o = 0; o < 3; o++) {
				partial = (pixman_fixed_32_32_t) l->matrix[dy][o] * (pixman_fixed_32_32_t) r->matrix[o][dx];
				v += partial >> 16;
			}
			if (v > pixman_max_fixed_48_16 || v < pixman_min_fixed_48_16)
				return FALSE;
			d.matrix[dy][dx] = (pixman_fixed_t) v;
		}
	*dst = d;
	return TRUE;
}

PIXMAN_EXPORT void
pixman_transform_init_scale (struct pixman_transform *t,
			     pixman_fixed_t sx,
			     pixman_fixed_t sy)
{
	memset (t, '\0', sizeof (struct pixman_transform));
	t->matrix[0][0] = sx;
	t->matrix[1][1] = sy;
	t->matrix[2][2] = F (1);
}

static pixman_fixed_t
fixed_inverse(pixman_fixed_t x)
{
	return (pixman_fixed_t) ((((pixman_fixed_48_16_t) F(1)) * F(1)) / x);
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_scale(struct pixman_transform *forward,
		       struct pixman_transform *reverse,
		       pixman_fixed_t sx, pixman_fixed_t sy)
{
	struct pixman_transform   t;

	if (sx == 0 || sy == 0)
		return FALSE;

	if (forward) {
		pixman_transform_init_scale (&t, sx, sy);
		if (!pixman_transform_multiply (forward, &t, forward))
			return FALSE;
	}
	if (reverse) {
		pixman_transform_init_scale (&t, fixed_inverse (sx),
					     fixed_inverse (sy));
		if (!pixman_transform_multiply (reverse, reverse, &t))
			return FALSE;
	}
	return TRUE;
}

PIXMAN_EXPORT void
pixman_transform_init_rotate(struct pixman_transform *t,
			     pixman_fixed_t c,
			     pixman_fixed_t s)
{
	memset(t, '\0', sizeof (struct pixman_transform));
	t->matrix[0][0] = c;
	t->matrix[0][1] = -s;
	t->matrix[1][0] = s;
	t->matrix[1][1] = c;
	t->matrix[2][2] = F (1);
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_rotate(struct pixman_transform *forward,
			struct pixman_transform *reverse,
			pixman_fixed_t c, pixman_fixed_t s)
{
	struct pixman_transform   t;
	
	if (forward) {
		pixman_transform_init_rotate(&t, c, s);
		if (!pixman_transform_multiply(forward, &t, forward))
			return FALSE;
	}

	if (reverse) {
		pixman_transform_init_rotate(&t, c, -s);
		if (!pixman_transform_multiply (reverse, reverse, &t))
			return FALSE;
	}
	return TRUE;
}

PIXMAN_EXPORT void
pixman_transform_init_translate(struct pixman_transform *t,
				pixman_fixed_t tx, pixman_fixed_t ty)
{
	memset(t, '\0', sizeof (struct pixman_transform));
	t->matrix[0][0] = F (1);
	t->matrix[0][2] = tx;
	t->matrix[1][1] = F (1);
	t->matrix[1][2] = ty;
	t->matrix[2][2] = F (1);
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_translate(struct pixman_transform *forward,
			   struct pixman_transform *reverse,
			   pixman_fixed_t tx, pixman_fixed_t ty)
{
	struct pixman_transform   t;

	if (forward) {
		pixman_transform_init_translate(&t, tx, ty);
		if (!pixman_transform_multiply(forward, &t, forward))
			return FALSE;
	}

	if (reverse) {
		pixman_transform_init_translate(&t, -tx, -ty);
		if (!pixman_transform_multiply(reverse, reverse, &t))
			return FALSE;
	}
	return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_bounds(const struct pixman_transform *matrix,
			struct pixman_box16 *b)
			
{
	struct pixman_vector v[4];
	int i;
	int x1, y1, x2, y2;

	v[0].vector[0] = F (b->x1);    v[0].vector[1] = F (b->y1);	v[0].vector[2] = F(1);
	v[1].vector[0] = F (b->x2);    v[1].vector[1] = F (b->y1);	v[1].vector[2] = F(1);
	v[2].vector[0] = F (b->x2);    v[2].vector[1] = F (b->y2);	v[2].vector[2] = F(1);
	v[3].vector[0] = F (b->x1);    v[3].vector[1] = F (b->y2);	v[3].vector[2] = F(1);
	for (i = 0; i < 4; i++)
	{
		if (!pixman_transform_point(matrix, &v[i]))
			return FALSE;
		x1 = pixman_fixed_to_int(v[i].vector[0]);
		y1 = pixman_fixed_to_int(v[i].vector[1]);
		x2 = pixman_fixed_to_int(pixman_fixed_ceil (v[i].vector[0]));
		y2 = pixman_fixed_to_int(pixman_fixed_ceil (v[i].vector[1]));
		if (i == 0)
		{
			b->x1 = x1; b->y1 = y1;
			b->x2 = x2; b->y2 = y2;
		}
		else
		{
			if (x1 < b->x1) b->x1 = x1;
			if (y1 < b->y1) b->y1 = y1;
			if (x2 > b->x2) b->x2 = x2;
			if (y2 > b->y2) b->y2 = y2;
		}
	}
	return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_invert (struct pixman_transform *dst,
			 const struct pixman_transform *src)
{
	struct pixman_f_transform m, r;

	pixman_f_transform_from_pixman_transform (&m, src);
	if (!pixman_f_transform_invert (&r, &m))
		return FALSE;
	if (!pixman_transform_from_pixman_f_transform (dst, &r))
		return FALSE;
	return TRUE;
}

static pixman_bool_t
within_epsilon(pixman_fixed_t a, pixman_fixed_t b, pixman_fixed_t epsilon)
{
	pixman_fixed_t  t = a - b;
	if (t < 0) t = -t;
	return t <= epsilon;
}

#define epsilon	(pixman_fixed_t) (2)

#define is_same(a,b) (within_epsilon(a, b, epsilon))
#define is_zero(a)   (within_epsilon(a, 0, epsilon))
#define is_one(a)    (within_epsilon(a, F(1), epsilon))
#define is_unit(a)   (within_epsilon(a, F( 1), epsilon) || \
		      within_epsilon(a, F(-1), epsilon) || \
		      is_zero(a))
#define is_int(a)    (is_zero(pixman_fixed_frac(a)))

PIXMAN_EXPORT pixman_bool_t
pixman_transform_is_identity(const struct pixman_transform *t)
{
	return ( is_same(t->matrix[0][0], t->matrix[1][1]) &&
		 is_same(t->matrix[0][0], t->matrix[2][2]) &&
		!is_zero(t->matrix[0][0]) &&
		 is_zero(t->matrix[0][1]) &&
		 is_zero(t->matrix[0][2]) &&
		 is_zero(t->matrix[1][0]) &&
		 is_zero(t->matrix[1][2]) &&
		 is_zero(t->matrix[2][0]) &&
		 is_zero(t->matrix[2][1]));
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_is_scale(const struct pixman_transform *t)
{
	return (!is_zero(t->matrix[0][0]) &&
		 is_zero(t->matrix[0][1]) &&
		 is_zero(t->matrix[0][2]) &&

		 is_zero(t->matrix[1][0]) &&
		!is_zero(t->matrix[1][1]) &&
		 is_zero(t->matrix[1][2]) &&

		 is_zero(t->matrix[2][0]) &&
		 is_zero(t->matrix[2][1]) &&
		!is_zero(t->matrix[2][2]));
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_is_int_translate(const struct pixman_transform *t)
{
	return (is_one (t->matrix[0][0]) &&
		is_zero(t->matrix[0][1]) &&
		is_int (t->matrix[0][2]) &&

		is_zero(t->matrix[1][0]) &&
		is_one (t->matrix[1][1]) &&
		is_int (t->matrix[1][2]) &&

		is_zero(t->matrix[2][0]) &&
		is_zero(t->matrix[2][1]) &&
		is_one (t->matrix[2][2]));
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_is_inverse(const struct pixman_transform *a,
			    const struct pixman_transform *b)
{
	struct pixman_transform   t;

	pixman_transform_multiply(&t, a, b);
	return pixman_transform_is_identity(&t);
}

PIXMAN_EXPORT void
pixman_f_transform_from_pixman_transform (struct pixman_f_transform *ft,
					  const struct pixman_transform *t)
{
	int	i, j;

	for (j = 0; j < 3; j++)
		for (i = 0; i < 3; i++)
			ft->m[j][i] = pixman_fixed_to_double (t->matrix[j][i]);
}

PIXMAN_EXPORT pixman_bool_t
pixman_transform_from_pixman_f_transform (struct pixman_transform *t,
					  const struct pixman_f_transform *ft)
{
	int	i, j;

	for (j = 0; j < 3; j++)
		for (i = 0; i < 3; i++)
		{
			double  d = ft->m[j][i];
			if (d < -32767.0 || d > 32767.0)
				return FALSE;
			d = d * 65536.0 + 0.5;
			t->matrix[j][i] = (pixman_fixed_t) floor (d);
		}
	return TRUE;
}

static const int	a[3] = { 3, 3, 2 };
static const int	b[3] = { 2, 1, 1 };

PIXMAN_EXPORT pixman_bool_t
pixman_f_transform_invert(struct pixman_f_transform *dst,
			  const struct pixman_f_transform *src)
{
	double  det;
	int	    i, j;
	static int	a[3] = { 2, 2, 1 };
	static int	b[3] = { 1, 0, 0 };

	det = 0;
	for (i = 0; i < 3; i++) {
		double	p;
		int	ai = a[i];
		int	bi = b[i];
		p = src->m[i][0] * (src->m[ai][2] * src->m[bi][1] -
				    src->m[ai][1] * src->m[bi][2]);
		if (i == 1)
			p = -p;
		det += p;
	}
	if (det == 0)
		return FALSE;
	det = 1/det;
	for (j = 0; j < 3; j++) {
		for (i = 0; i < 3; i++) {
			double  p;
			int	    ai = a[i];
			int	    aj = a[j];
			int	    bi = b[i];
			int	    bj = b[j];

			p = (src->m[ai][aj] * src->m[bi][bj] -
			     src->m[ai][bj] * src->m[bi][aj]);
			if (((i + j) & 1) != 0)
				p = -p;
			dst->m[j][i] = det * p;
		}
	}
	return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_f_transform_point(const struct pixman_f_transform *t,
			 struct pixman_f_vector *v)
{
	struct pixman_f_vector    result;
	int			    i, j;
	double		    a;

	for (j = 0; j < 3; j++)
	{
		a = 0;
		for (i = 0; i < 3; i++)
			a += t->m[j][i] * v->v[i];
		result.v[j] = a;
	}
	if (!result.v[2])
		return FALSE;
	for (j = 0; j < 2; j++)
		v->v[j] = result.v[j] / result.v[2];
	v->v[2] = 1;
	return TRUE;
}

PIXMAN_EXPORT void
pixman_f_transform_point_3d(const struct pixman_f_transform *t,
			    struct pixman_f_vector *v)
{
	struct pixman_f_vector    result;
	int			    i, j;
	double		    a;

	for (j = 0; j < 3; j++)
	{
		a = 0;
		for (i = 0; i < 3; i++)
			a += t->m[j][i] * v->v[i];
		result.v[j] = a;
	}
	*v = result;
}

PIXMAN_EXPORT void
pixman_f_transform_multiply(struct pixman_f_transform *dst,
			    const struct pixman_f_transform *l,
			    const struct pixman_f_transform *r)
{
	struct pixman_f_transform d;
	int			    dx, dy;
	int			    o;

	for (dy = 0; dy < 3; dy++)
		for (dx = 0; dx < 3; dx++)
		{
			double v = 0;
			for (o = 0; o < 3; o++)
				v += l->m[dy][o] * r->m[o][dx];
			d.m[dy][dx] = v;
		}
	*dst = d;
}

PIXMAN_EXPORT void
pixman_f_transform_init_scale (struct pixman_f_transform *t, double sx, double sy)
{
	t->m[0][0] = sx;	t->m[0][1] = 0;	    t->m[0][2] = 0;
	t->m[1][0] = 0;	t->m[1][1] = sy;    t->m[1][2] = 0;
	t->m[2][0] = 0;	t->m[2][1] = 0;	    t->m[2][2] = 1;
}

PIXMAN_EXPORT pixman_bool_t
pixman_f_transform_scale (struct pixman_f_transform *forward,
			  struct pixman_f_transform *reverse,
			  double sx, double sy)
{
	struct pixman_f_transform t;

	if (sx == 0 || sy == 0)
		return FALSE;

	if (forward) {
		pixman_f_transform_init_scale (&t, sx, sy);
		pixman_f_transform_multiply (forward, &t, forward);
	}
	if (reverse) {
		pixman_f_transform_init_scale (&t, 1/sx, 1/sy);
		pixman_f_transform_multiply (reverse, reverse, &t);
	}
	return TRUE;
}

PIXMAN_EXPORT void
pixman_f_transform_init_rotate (struct pixman_f_transform *t, double c, double s)
{
	t->m[0][0] = c;	t->m[0][1] = -s;    t->m[0][2] = 0;
	t->m[1][0] = s;	t->m[1][1] = c;	    t->m[1][2] = 0;
	t->m[2][0] = 0;	t->m[2][1] = 0;	    t->m[2][2] = 1;
}

PIXMAN_EXPORT pixman_bool_t
pixman_f_transform_rotate (struct pixman_f_transform *forward,
			   struct pixman_f_transform *reverse,
			   double c, double s)
{
	struct pixman_f_transform t;

	if (forward) {
		pixman_f_transform_init_rotate (&t, c, s);
		pixman_f_transform_multiply (forward, &t, forward);
	}
	if (reverse) {
		pixman_f_transform_init_rotate (&t, c, -s);
		pixman_f_transform_multiply (reverse, reverse, &t);
	}
	return TRUE;
}

PIXMAN_EXPORT void
pixman_f_transform_init_translate (struct pixman_f_transform *t, double tx, double ty)
{
	t->m[0][0] = 1;	t->m[0][1] = 0;	    t->m[0][2] = tx;
	t->m[1][0] = 0;	t->m[1][1] = 1;	    t->m[1][2] = ty;
	t->m[2][0] = 0;	t->m[2][1] = 0;	    t->m[2][2] = 1;
}

PIXMAN_EXPORT pixman_bool_t
pixman_f_transform_translate (struct pixman_f_transform *forward,
			      struct pixman_f_transform *reverse,
			      double tx, double ty)
{
	struct pixman_f_transform t;

	if (forward) {
		pixman_f_transform_init_translate (&t, tx, ty);
		pixman_f_transform_multiply (forward, &t, forward);
	}
	if (reverse) {
		pixman_f_transform_init_translate (&t, -tx, -ty);
		pixman_f_transform_multiply (reverse, reverse, &t);
	}
	return TRUE;
}

PIXMAN_EXPORT pixman_bool_t
pixman_f_transform_bounds(const struct pixman_f_transform *t, struct pixman_box16 *b)
{
	struct pixman_f_vector    v[4];
	int			    i;
	int			    x1, y1, x2, y2;

	v[0].v[0] = b->x1;    v[0].v[1] = b->y1;	v[0].v[2] = 1;
	v[1].v[0] = b->x2;    v[1].v[1] = b->y1;	v[1].v[2] = 1;
	v[2].v[0] = b->x2;    v[2].v[1] = b->y2;	v[2].v[2] = 1;
	v[3].v[0] = b->x1;    v[3].v[1] = b->y2;	v[3].v[2] = 1;
	for (i = 0; i < 4; i++)
	{
		if (!pixman_f_transform_point (t, &v[i]))
			return FALSE;
		x1 = floor (v[i].v[0]);
		y1 = floor (v[i].v[1]);
		x2 = ceil (v[i].v[0]);
		y2 = ceil (v[i].v[1]);
		if (i == 0)
		{
			b->x1 = x1; b->y1 = y1;
			b->x2 = x2; b->y2 = y2;
		}
		else
		{
			if (x1 < b->x1) b->x1 = x1;
			if (y1 < b->y1) b->y1 = y1;
			if (x2 > b->x2) b->x2 = x2;
			if (y2 > b->y2) b->y2 = y2;
		}
	}
	return TRUE;
}

PIXMAN_EXPORT void
pixman_f_transform_init_identity (struct pixman_f_transform *t)
{
	int	i, j;

	for (j = 0; j < 3; j++)
		for (i = 0; i < 3; i++)
			t->m[j][i] = i == j ? 1 : 0;
}
